One skilled in the art of subterranean plow blades, or the plow blade for laying cable beneath the surface, is already aware of the variety of configurations and multiple pieces utilized for providing the plow blade itself. That is, the configurations are complex and virtually unlimited in their variety, and the blades are also made of two or more pieces. Therefore, the prior art blades are complex and difficult to manufacture and maintain and are inefficient in their use, and they require the manufacture and assembly of two or more parts, at least in those types of blades. U.S. patents which generally show plow blades having sharpened edges extending along the leading edge and to the very lower tip thereof, and which show various means for assembling or mounting the blade relative to a tractor, are U.S. Pat. Nos. 3,363,423 and 3,390,533 and 3,744,260 and 3,851,489.
U.S. patents which generally show plow blades having irregular and complex sharpened leading edges and some of which show the blade made in two or more pieces are U.S. Pat. Nos. 2,632,265 and 2,925,872 and 3,066,491 and 3,326,009 and 3,341,253 and 3,405,533 and 3,486,344 and 3,497,016 and 3,575,006. Also, all of the aforesaid patents show various means for assembling and securing a blade with a tractor unit or the like.
The present invention provides a subterranean plow blade apparatus which is readily and easily manufactured in that it is a one piece blade and is sharpened along a straight line on its leading edge, and arrangement is made for ready and easily assembly and disassembly with a tractor unit. That is, the blade of this invention can be readily clamped to a tractor and it can be readily released therefrom, and no special alignment holes or bolting or the like is required.
In addition to providing a plow blade which can be readily and easily attached and removed from a tractor, the present invention provides a blade which reduces friction with the soil and which increases soil fracture. In accomplishing these objectives, the plow blade of this invention is made with only the intermediate length of its leading portion sharpened, and thus the unsharpened or square edge presents a smaller surface to the effects of friction and it eliminates the wedging effect of a sharpened edge. The soil in front of the blade is fractured to a greater extent by the square edge when the shaker box pulls the blade upward in the soil. The loosened soil flows upward along the leading edge and is relieved by the short sharpened section which terminates slightly below ground level. This sharpened portion reduces heaving at the soil surface.
These and other objects and advantages will become apparent upon reading the following description in light of the accompanying drawing.